• Login
    JavaScript is disabled for your browser. Some features of this site may not work without it.
    The erodibility of fine sediment deposits in lowland chalk streams 
    •   QMRO Home
    • Queen Mary University of London Theses
    • Theses
    • The erodibility of fine sediment deposits in lowland chalk streams
    •   QMRO Home
    • Queen Mary University of London Theses
    • Theses
    • The erodibility of fine sediment deposits in lowland chalk streams
    ‌
    ‌

    Browse

    All of QMROCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects
    ‌
    ‌

    Administrators only

    Login
    ‌
    ‌

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    The erodibility of fine sediment deposits in lowland chalk streams

    View/Open
    GRABOWSKIErodibilityOfFine2011.pdf (3.303Mb)
    Metadata
    Show full item record
    Abstract
    Lowland chalk streams in the UK are experiencing increased deposition of fine sediment due to changes in land-use practices, channel modifications, and groundwater abstraction. The fine sediment is linked to benthic habitat degradation, the obstruction of surface-groundwater flow, and the storage of contaminants, such as nutrients and pesticides. Whilst research has been conducted on the provenance, transport, deposition, and storage of fine sediment in chalk streams, none has expressly investigated erosion. To help fill this gap in knowledge, a yearlong field survey was conducted in two reaches of the Frome-Piddle Catchment (Dorset) to quantify the erodibility of surficial fine sediment deposits. Sediment erodibility was measured in the field using a cohesive strength meter (CSM) and a shear vane. These measurements were paired with sediment cores for analysis of the physical, chemical and biological properties of the sediment. The large environmental dataset was analysed using a comprehensive suite of modern analytical techniques, including regression trees, linear regression, and mixed effects modelling. The results indicate that the erodibility of fine sediment varies significantly over time and within a stream reach due to variations in hydraulic conditions and sediment properties. Effective particle size and chlorophyll-a content were identified as the major sediment properties influencing CSM-derived erodibility, whereas root density was key for shear vane-derived strength. To date, the erosion thresholds generated by CSMs have been largely restricted to relative uses, and a calibration based on cohesive sediment is needed to permit their future incorporation into sediment transport models. This study developed an empirical calibration using laboratory experiments that estimated critical shear stress from CSM-derived erosion thresholds. By quantifying the erodibility of fine sediment deposits in chalk streams, and representing the erosion thresholds as critical shear stress, we can better gauge their local environmental impacts and help to inform models of fine sediment transport
    Authors
    Grabowski, Robert Carl
    URI
    https://qmro.qmul.ac.uk/xmlui/handle/123456789/707
    Collections
    • Theses [3321]
    Copyright statements
    The copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the author
    Twitter iconFollow QMUL on Twitter
    Twitter iconFollow QM Research
    Online on twitter
    Facebook iconLike us on Facebook
    • Site Map
    • Privacy and cookies
    • Disclaimer
    • Accessibility
    • Contacts
    • Intranet
    • Current students

    Modern Slavery Statement

    Queen Mary University of London
    Mile End Road
    London E1 4NS
    Tel: +44 (0)20 7882 5555

    © Queen Mary University of London.